Charge forming means for an internal combustion engine



1959 R. c. GROVES 2,869,527

CHARGE FORMING MEANS FOR AN INTERNAL COMBUSTION ENGINE Filed July 12, 1956 4 Sheets-Sheet 1 r Q E E E E v E N l N & x 4 ll fay g opw ATTORNEY Jan. 20, 1959 c. GROVES 2,869,527

CHARGE FORMING MEANS FOR AN INTERNAL. COMBUSTION ENGINE Filed July 12, 1956 4 Sheets-Sheet 2 INVENTOR ATTORNEY Jan. 20, 1959 R3; 0. GROVES 2,869,527

CHARGE FORMING MEANS FpR AN INTERNAL CQMBUSTION ENGINE Filed July 12, 1956 4 Sheets-Sheet 5 INVENTOR ATTORNEY Jan. 20, 1959 R. c. GRoyE 2,869,527

CHARGE FORMING MEANS FOR AN INTERNAL. COMBUSTION ENGINE Filed July 12, 1956 4 Sheets-Sheet 4 INVENTOR CHARGE FURMING MEANS FOR AN INTERNAL CGMBUSTION ENGINE Ronald C. Groves, Grandville, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application July 12, 1956, Serial No. 597,456

Claims. (Cl. 123-119) The present invention relates to internal combustion engines and more particularly to fuel supply systems for injecting metered quantities offuel to the cylinders of the engine.

In the operation of an internal combustion engine of the so-called spark ignited variety, a combustible charge of air and fuel is compressed and ignited in the engine. In order to obtain the maximum efficiency and performance from such an engine, it is essential that the charges in the various cylinders be of substantially identical volume and of substantially identical proportions. One means of accomplishing this is to employ a fuel injection system in which metered fuel is injected into the charge in proportion to the fuel requirements of the engine adjacent the engine cylinders. I-Ieretofore, such systems have been very expensive, complicated, unreliable in operation and generally unsuited for use on modern automotive engines.

't is now proposed to provide a simple, inexpensive fuel injection system which is particularly adapted for use on mass produced automotive engines. in the present instance this system includes a pump driven by the engine and discharges fuel into a metering control which is connected to a fuel distributor. The pump discharges fuel as a function of the engine speed while the metering control includes a pair of orifices which are disposed in parallel with each other and effective to meter the fuel by bypassing the surplus fuel for return to the fuel source. One of these orifices may have a fixed area while the area of the other orifice varies in response to the pressure differential thereacross. The distributor may have a valve therein which is operatively interconnected with the throttle means to adjust the valve as a function of the setting of the throttle means.

In order to obtain the maximum performance from an engine, it is essential that all of the engine cylinders obtain charges of a maximum volume. Heretofore, such engines have employed induction systems having various configurations of induction passages which have impaired the charging of the cylinders by limiting the air flow and causing a nonuniformity of the charge.

It is now proposed to provide an induction system for an engine in which all of the induction passages are sub stantially identical to each other and that, are adapted to resonate during one or more engine operating conditions. During such conditions there will be surges of air in the induction passages that will tend to supercharge the cylinders.

In the four sheets of drawings:

Figure l is a fragmentary plan view of an engine employing charge forming means embodying the present invention.

Figure 2 is a fragmentary end view of the engine in Figure 1.

Figure 3 is a diagrammatic view of the fuel injection system employed on the engine of Figures 1 and 2.

Figure 4 is a cross sectional view of the metering control employed in this system and is taken substantially along the plane of line 4--4 in Figure 2.

2%69527' Patented Jan. 20,

Figure 5 is a cross sectional view of the fuel distributor employed in the foregoing system and taken substantially along the plane of line 55 in Figure 2.

Figure 6 is a cross sectional view of the fuel distributor taken substantially along the plane of line 66 in Figure 5.

Referring to the drawings in more detail the present invention may be adapted to be employed on any suitable internal combustion engine. In the present instance this engine 10 is of the so-called V-type wherein the cylinder block l2 includes a pair of angularly disposed banks 14 of cylinders. A separate cylinder head 16 is secured to each of the faces 18 extending along the tops of the banks 14 of cylinders. These cylinder heads 16 include cavities which are positioned to register with the open ends of the cylinders and to thereby form combustion chambers. The heads 16 also include intake passages 20 that extend therethrough and communicate with the combustion chambers. Intake valves may be disposed at the ends of the intake passages 20 and actuated by the engine camshaft for timing the charging of the cylinders.

In order to charge the cylinders with air an induction system 22 may be provided which is adapted to draw the induction air from the atmosphere and deliver it into the cylinders. The present induction system 22 includes a pair of throttle bodies 24 having plates 26 that are secured to the sides of the cylinder heads 16 by bolts 28. Extensions 3t? project from the plates 26 and have passages 32 that extend therethrough to register with the intake passages Zd in the cylinder heads 16. In order to control the volume of the charge flowing into the cylinders, throttle valves 34 may be disposed in each of the passages 32 in the extensions 30. These throttle valves 34 are of the butterfly type and are mounted on flat spots on throttle shafts 36 extending the entire length of the throttle bodies 24. The angular position of the throttle shafts 36 and throttle valves 34 are controlled by an adjustable linkage 38. Separate tubes or ram pipes 40 have the inner ends secured to the flanges on the ends of the extensions 30. The outer ends of these pipes 40 open into the atmosphere to draw induction air therefrom. In order to decrease the over-all height of the engine, the ram pipes 40 may be slightly bent. In order to increasethe volumetric efficiency of the induction system 22 the ram pipes 40, the passages 32 through the throttle bodies 24, and the intake passages 20 in the cylinder heads 16 are all of substantially the same-length and are preferably tuned to resonate during one or more engine operating conditions. During such conditions there will be surges in these passages which will tend to dynamically supercharge the engine and thereby materially increase the volumetric efiiciency of the induction system.

In order to form the combustible charge a fuel injection system 42 may be provided which will inject metered quantitles of fuel into the passages adjacent the intake valves in proportion to the fuel requirements of the engine.

In the present instance this system 42 includes a fuel storage tank 44, a fuel pump 46, a metering control 48, a distributor 50 and a plurality of injector nozzles 52. The fuel pump'46 may be of any desired variety; how ever, it is preferably a positive displacement pump having an output which is a function of the engine speed.

The metering control 48 includes a housing 54 having a fuel inlet 56 which is adapted to be interconnected with the fuel pump 46, a metered fuel outlet 58 which is adapted to be interconnected with the distributor 50 and a. spill fuel outlet 60 which is adapted to be interconnected with the storage tank 44. A fuel passage 62 extends through the housing 54 and directly interconnects the inlet 56 with the metered fuel outlet 58 so that the fuel may flow therethrough free from any form of restriction.

A second passage 64 may extend from the first passage 62 t the spill fuel outlet 60 for by-passing fuel for return to the storage tank 44. A member 66 may be disposed in this passage 62 and have a restriction such as an orifice 68 of some predetermined fixed area that is effective to regulate the flow of fuel by-passed therethrough.

'In addition, a second orifice 70 may be provided in parallel with the fixed area orifice and also interconnect the first passage 62 with the second passage 64 to allow an additional quantity of fuel to be by-passed for return to the storage tank 44. This orifice 70 has a variable area and is formed by an assembly 72 slidably disposed in a drilled passage 74 extending longitudinally therethrough a member 76. A pair of opposed springs 73 acting on the opposite ends of the assembly 72 will cause it to assume some position within the drilled passage 74. Since one end of the. assembly 72'will be exposed to the fuel pressure upstream of the orifices 6S and 70 and the other end exposed to the fuel pressure downstream of the orifices, there will be a pressure differential across the assembly 72. This differential will act against the springs 78 and cause the assembly 72 to move as a function of this differential. A plug 80 having an extension 82 thereon may bevthreaded into the end of the passage 74 through the member 76 so that the extension 82 projects into the open end of the assembly 72. The end of the extension 82 includes a tapered needle portion 84 adjacent the orifice 70. Thus as the assembly 72 slides in the passage 74 in response to the pressure differential thereacross the effective area of this orifice 70 will vary.

The distributor 50 comprises a housing 86 that forms a base for the metering control 48 and it includes an inlet passage 88 which is ada ted to be interconnected with the metered fuel outlet 58 of the metering control unit 48. This inlet passage 88 extends through the distributor 50 and into a distributing chamber 90 so that the metered fuel will be delivered to the chamber 90. A rotary valve 92 operatively interconnected with the throttle means by the arm 94 and push-rod 96 attached to the throttle shafts 36 is disposed in the inlet passage 88 and presents a variable restriction 97 to the flow of fuel therethrough. A plurality of radial passages 95 may radiate from the distributing chamber 90 and feed the metered fuel into the injector lines 98. The outer ends of these injector lines 93 are connectedv to injector nozzles 52 which are disposed in the intake passages. The present nozzles 52 include a longitudinal passage 102 having a filter 104 therein and a'jet 106 which is adapted to direct a fine stream of fuel onto a deflector 198. The deflector 108 is positioned to break the stream of fuel into fine particles and deflect them down the intake passage towards the intake valves. It has been found desirable to place the nozzles adjacent the intake valves and to direct the stream of fuel in the same direction as the air flow. This will tend to minimize the wetting of the surfaces of the induction passage with fuel.

From the foregoing it will be seen that a simple and economical fuel injection system has been provided. The fuel is metered by by-passing the surplus fuel through the orifices 68 and 70 for return to the fuel tank 44. The amount of by-passed fuel is dependent upon the areas of the orifices'd and 7t and the pressure thereacross. The area of the variable area orifice 70 is dependent upon the fuel pressure which, in .turn, is dependent upon the pump speed and the resistance of the rotary valve 92 in the distributor 50.

It is to be understood that, although the'invention has been described with specific reference to a particular embodiment thereof, it is not to be so limited since changes and alterations therein may be made which are within the full intended scope of this invention as defined by the appended claims.

I claim:

1. A fuel injection system for an internal combustion engine comprising a fuel pump having an outlet for discharging fuel therefrom, said outlet being adapted to be interconnected with a fuel distributor for distributing equal increments of fuel to the engine cylinders, a fixed restriction interconnected with said outlet for by-passing a portion of the fuel from said outlet for return to the source of fuel, a variable restriction disposed in parallel with said fixed restriction for by-passing an additional amount of fuel to said source, said last mentioned restriction being responsive to the pressure difierential across said restrictions for varying the resistance of said second restriction in proportion thereto.

2. A fuel injection system for an internal combustion engine comprising a fuel pump having an outlet for discharging fuel therefrom, said outlet being adapted to be interconnected with a fuel distributor for distributing equal increments of fuel to the engine cylinders, a fixed area orifice interconnected with said outlet for by-passing a portion of the fuel from said outlet for return to the source of fuel, a variable area orifice disposed in parallel with said first orifice for by-passing an additional amount of fuel to said source, means responsive to the pressure differential across said orifices for varying the area of said second orifice in proportion to said pressure differential.

3. In an internal combustion engine having an induction system for charging the engine cylinders and a throttle valve for regulating the volume of said charge, a fuel injection system comprising a fuel pump driven by said engine and having an outlet for discharging fuel therefrom as a function of the speed of said engine for distribution to the engine cylinders, a fixed restriction interconnected with said outlet for by-passing a portion of said fuel for return to the fuel source, a variable restriction disposed in parallel with said first restriction for by-passing an additional amount of fuel to said source, said last mentioned restriction being responsive to the pressure differential across said restrictions for varying the resistance of said second restriction in proportion thereto.

4. In a multicylinder, internal combustion engine having an induction system for charging said cylinders and throttle means for regulating the volume of said charge, a fuel injection system comprising a fuel pump having an outlet for discharging fuel therefrom as a function of the engine speed, a distributor interconnected with said pump outlet for distributing equal increments of fuel to the engine cylinders, a fixed restriction interconnected with said outlet for by-passing a portion of the fuel from said distributor forreturn to the source of fuel, a variable restriction disposed in parallel with said fixed restriction for by-passing an additional amount of fuel to said source, said last mentioned restriction being responsive to the pressure differential across said restrictions for varying the resistance of said second restriction in proportion thereto, said distributor including a variable restriction operatively interconnected with said throttle means.

5. A fuel injection system for an internal combustion engine comprising a fuel pump having an outlet for discharging fuel therefrom, a metering control interconnected with said outlet and having a pair of orifices disposed in parallel with each other for by-passing at least a portion of the fuel from said pump for return to the fuel source, one of said orifices having a fixed area and the other having a variable area, means effective to distribute the remaining fuel to said cylinders, said variable area orifice being responsive to the fuel pressure thereacross for varying the area of said orifice in proportion thereto.

6. In a multicylinder, internal combustion engine having an induction system including intake passages for charging said cylinders and throttle means for regulating the volume of said charge, ajfuel injection system comprising a fuel pump driven by said engine for discharging fuel therefrom as a function of the engine speed, a metering control interconnected with said outlet and having a fixed restriction and a variable restriction disposed in parallel with each other and adapted to by-pass at least a portion of the fuel from said pump for return to the fuel source, means effective to distribute the remaining fuel to said cylinders, said variable restriction being responsive to the pressure difierential thereacross for varying said restriction in proportion thereto, said intake passages being tuned to resonate during at least one engine operating condition for dynamically supercharging said cylinders.

7. A metering control for use in a fuel injection system for an internal combustion engine, said control comprising a housing having an inlet adapted to be interconnected with the outlet of the fuel pump, a metered fuel outlet adapted to discharge metered fuel therefrom for distribution to the engine cylinders and a surplus fuel outlet adapted to discharge fuel for return to said pump, a passage interconnecting said inlet with said metered fuel outlet, a fixed area orifice interconnecting said passage with said surplus fuel outlet, a variable area orifice disposed in parallel to said first orifice and interconnecting said passage with said last mentioned outlet, said second orifice being responsive to the pressure differential across said orifices for varying the area thereof in response to said pressure differential.

8. In a multicylinder, internal combustion engine having an induction system with intake passages for charging said cylinders and throttle means for regulating the volume of said charge, a fuel injection system comprising a pump driven by said engine for discharging fuel as a function of engine speed, a metering control interconnected with said pump including a fixed area orifice and a variable area orifice disposed in parallel for by-passing the surplus portion of the fuel for return to said pump, a fuel distributor interconnected with said control for dividing the remaining portion of the fuel into equal increments, injector nozzles disposed in said intake passages downstream of said throttle means for directing streams of fuel in the direction of said cylinders, said intake passages being adapted to resonate during one or more engine operating conditions for supercharging said cylinders.

9. An induction system for a multicylinder, internal combustion engine comprising a plurality of substantially identical intake passages having the outlet ends thereof adapted to communicate with said cylinders in said engine for charging said cylinders, said intake passages being tuned to cause the flow therein to resonate during at least one engine operating condition, throttle means for regulating the volume of the charge flowing through said passages and delivered to said cylinders, said intake passages being adapted to have a stream of atomized fuel directed thereinto downstream from said throttle means for mixing with the air therein to form a combustible charge.

10. An induction system for a multicylinder, internal combustion engine comprising a separate intake passage for each of said cylinders, the inlet ends of said passages being adapted to communicate with the atmosphere and the outlet ends thereof being adapted to communicate with said cylinders in said engine for charging said cylinders, said intake passages being tuned to cause the flow therein to resonate during at least one engine operating condition for dynamically supercharging said cylinders, a separate throttle valve in eachof said intake passages for regulating the volume of the charge flowing through said passages and delivered to said cylinders, control means for simultaneously actuating all of said throttle valves in unison, said intake passages being adapted to have a stream of atomized fuel directed thereinto downstream from said throttle valves for mixing with the air therein to form a combustible charge.

11. Charge forming means for use on an internal combustion engine having a plurality of cylinders and intake valves for regulating the fiow of said charge into said cylinders, said charge forming means comprising a plurality of intake passages having the inner ends thereof communicating with said intake valves, said intake passages being tuned to cause the flow therein to to resonate during at least one engine operating condition, throttle means for regulating the volume of said charge flowing through said intake passages and fuel nozzles communicating with said intake passages downstream from said throttle means for injecting metered quantities of fuel into said charge.

12. Charge forming means for use on an internal combustion engine having a plurality of cylinders and intake valves for timing the flow of the charges into said cylinders, said charge forming means comprising separate intake passages for each of said cylinders with the inner ends of each of said passages being adapted to communicate with said intake valves, said intake passages being tuned to cause the flow therein to resonate during at least one engine operating condition for dynamically supercharging said cylinders, separate throttle valves in said intake passages for regulating the volume of said charge flowing through said intake passages, control means for simultaneously actuating all of said throttle valves in unison, and fuel nozzles communicating with said intake passages downstream from said throttle valves for injecting metered quantities of fuel into said charge.

13. In an internal combustion engine having a cylinder block with a plurality of cylinders, charge forming means comprising intake valves communicating with each of said cylinders, separate intake passages for each of said cylinders with the inner ends thereof being adapted to communicate with said cylinders, said intake passages being substantially identical to each other and being tuned to cause the flow therethrough to resonate during at least one engine operating condition for dynamically supercharging said cylinders, throttle means for regulating the volume of the charge flowing through said intake passages and into said cylinders and fuel means responsive to the fuel demands of said engine and being effective to meter fuel in proportion thereto, said fuel means including discharge nozzles disposed in eachof said intake passages downstream from said throttle means for discharging said metered fuel into said passages to form a combustible charge.

14. In an internal combustion engine having a cylinder block having a plurality of cylinders, charge forming means comprising an intake valve communicating with each of said cylinders, 21 separate intake passage for each of said cylinders, the inlet ends of each of said passages opening into the atmosphere and the outlet ends thereof communicating with said intake valves, said intake passages being substantially identical to each other and being tuned to cause the flow therethrough to resonate during at least one engine operating condition,-a separate throttle valve in each of said passages for regulating the volume of the charge flowing therethrough and into said cylinders, control means for simultaneously actuating all of said throttle valves in unison, fuel means responsive to the fuel demands of said engine and effective to meter the fuel in proportion thereto, said fuel means including discharge nozzles disposed in each of said intake passages between said throttle valves and said inlet valves for discharging said metered fuel into said intake passages to form a combustible charge therein.

15. In an internal combustion engine having a cylinder block with a pair of angularly disposed banks of cylinders, charge forming means comprising intake valves communicating with each of said cylinders, a separate throttle body for each of said banks of cylinders having passages therethrough communicating with said intake valves, separate throttle valves disposed in each of said pasages for regulating the volume of the charge flowing into said cylinders, ram pipes secured to said throttle streams of atomized fuel into said passages to form 21 bodies so as to'communicate with .said passages and being combustible charge therein. tuned to cause the flow therethr'ough to resonate during s at least one engine operating condition for dynamically Referen e Cited-in the file of thi patent supercharging said cylinders, fuel means responsive to a the fuel demands of said engine and effective to meter UNITED STATES PATENTS the fuel flow in proportion thereto, said fuel means in- 2,136,959 Winfield Nov. 15, 1938 eluding discharge nozzles mounted on said throttle bodies 2,502,679 Stanly Apr. 4, 1950 and communicating with said intake passages between 2,673,556 Reggio Mar. 30, 1954 said throttle valves and said inlet valves for-discharging 10 

